Indonesian authorities have issued a tsunami warning and raised the alert for Mount Ruang to the highest level after the volcano near Sulawesi Island had multiple large eruptions over the past two days. The heightened alert was issued late on Wednesday after the the 725-meter-high volcano had two large eruptions earlier in the day, spewing a column of ash 3,000 metres into the sky. The head of Center for Volcanology and Geological Hazard Mitigation (PVMBG), Hendra Gunawan, said that authorities urged people living in the coastal area of neighboring Tagulandang island to remain alert for a pote…